1. Field of the Invention
The present invention is related to thermosettable compositions made from polyfunctional aliphatic and/or cycloaliphatic epoxy resins and to thermosets made from said thermosettable compositions.
2. Description of Background and Related Art
Epoxidation of aliphatic and cycloaliphatic alcohols is an area of long standing interest, for example as described in EP 0 121 260. Disclosed in EP 0 121 260 are examples of phase transfer catalyzed epoxidation of aliphatic diols, including cyclohexanedimathanol, using epichlorohydrin with quaternary ammonium halide catalysts.
WO2009/142901, incorporated herein by reference, describes an epoxy resin composition prepared from a mixture of cis-, trans-1,3- and 1,4-cyclohexanedimethanols using several epoxidation processes. WO/2009/142901 also discloses examples of preparing various distilled grades of the monoglycidyl ethers and diglycidyl ethers of cis-, trans-1,3- and 1,4-cyclohexanedimethanols, including a high purity (>99 wt %) diglycidyl ether of cis-, trans-1,3- and 1,4-cyclohexanedimethanols.
WO2009/142900, incorporated herein by reference, describes an epoxy resin reactive diluent composition prepared from a mixture of a first epoxy resin comprising an epoxy resin of cis-, trans-1,3- and 1,4-cyclohexanedimethanols and a second epoxy resin comprising one or more epoxy resins other than the first epoxy resin.
When using the prior art chemistry and processes to manufacture aliphatic and cycloaliphatic epoxy resins via epoxidation of aliphatic and cycloaliphatic hydroxyl containing materials with an epihalohydrin, it is difficult if not impossible, to drive to full conversion; and the processes produce significant quantities of oligomeric co-products (as much as 25 weight percent (wt %)-40 wt % of the epoxy resin composition). The components of the epoxy resin may include for example unconverted aliphatic and cycloaliphatic hydroxyl containing material reactant, monoglycidyl ether, diglycidyl ether, oligomeric co-products, and the like. While various methods, such as for example distillation, are operable for removing the desired high purity diglycidyl ether of cis-, trans-1,3- and 1,4-cyclohexanedimethanols from the undesirable oligomeric co-products, no satisfactory solution exists for handling the resulting separated and isolated oligomeric co-products. The solution to date has been to use the as produced mixture of the aliphatic and cycloaliphatic epoxy resins and the oligomeric co-products together as a reactive diluent for other epoxy resins where the oligomeric co-products are simply carried into the total diluent and epoxy resin composition. Problems with this approach include preparing an epoxy resin product having a higher than desirable viscosity induced by the presence of the oligomeric co-products and having a reduced reactivity with curing agents.
In view of the problems with prior art processes, it would be highly desirable to be able to fractionate an aliphatic or cycloaliphatic epoxy resin into monoglycidyl ether, diglycidyl ether, and the like, such that any residual oligomeric co-products fraction can be advantageously utilized to provide novel thermosettable compositions and thermosets based on the residual oligomeric co-products fraction.